The structural ordering in various forms of amorphous selenium has been studied by means of far-infrared measurements on the two types of spectrum, corresponding to the Se^8-ring component and the polymeric chain. The chemical extraction method of the Se^8-ring component by CS_2 is re-examined in terms of the spectroscopic analysis which shows that the ring component can not be extracted entirely from the mixture of the ring and the chain. A polycrystalline trigonal selenium is obtained from the component extracted from the vitreous selenium quenched at a high temperature above 700℃. Black amorphous selenium is obtained by heat treatment of red one. The spectra for both of the amorphous states show that they consist of similar mixtures of the ring and the chain components, so that the transition from red to black does not correspond to the structural change from the ring to the chain nor vice versa
